Catheter with single axial sensors

ABSTRACT

A catheter has single axis sensors mounted directly along a portion of the catheter whose position/location is of interest. The magnetic based, single axis sensors are on a linear or nonlinear single axis sensor (SAS) assembly. The catheter includes a catheter body and a distal 2D or 3D configuration provided by a support member on which at least one, if not at least three single axis sensors, are mounted serially along a length of the support member. The magnetic-based sensor assembly may include at least one coil member wrapped on the support member, wherein the coil member is connected via a joint region to a respective cable member adapted to transmit a signal providing location information from the coil member to a mapping and localization system. The joint region provides strain relief adaptations to the at least one coil member and the respective cable member from detaching.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to and thebenefit of U.S. application Ser. No. 14/445,021 filed Jul. 28, 2014, nowU.S. Pat. No. 10,405,774, which is a continuation of and claims priorityto and the benefit of U.S. application Ser. No. 12/982,765 filed Dec.30, 2010, now U.S. Pat. No. 8,792,962, the entire contents of all ofwhich are incorporated herein by reference.

FIELD OF INVENTION

This invention relates to a catheter, in particular, a catheter havinglocation sensors mounted on flexible distal end portion for improvedposition sensing of the distal end portion.

BACKGROUND

Electrode catheters have been in common use in medical practice for manyyears. They are used to stimulate and map electrical activity in theheart and to ablate sites of aberrant electrical activity. Atrialfibrillation is a common sustained cardiac arrhythmia and a major causeof stroke. This condition is perpetuated by reentrant waveletspropagating in an abnormal atrial-tissue substrate. Various approacheshave been developed to interrupt wavelets, including surgical orcatheter-mediated atriotomy. Prior to treating the condition, one has tofirst determine the location of the wavelets. Various techniques havebeen proposed for making such a determination, including the use ofcatheters with a mapping assembly that is adapted to measure activitywithin a pulmonary vein, coronary sinus or other tubular structure aboutthe inner circumference of the structure. One such mapping assembly hasa tubular structure comprising a generally circular main regiongenerally transverse and distal to the catheter body and having an outercircumference and a generally straight distal region distal to the mainregion. The tubular structure comprises a non-conductive cover over atleast the main region of the mapping assembly. A support member havingshape-memory is disposed within at least the main region of the mappingassembly. A plurality of electrode pairs, each comprising two ringelectrodes, are carried by the generally circular main region of themapping assembly.

In use, the electrode catheter is inserted into a guiding sheath whichhas been positioned a major vein or artery, e.g., femoral artery, andguided into a chamber of the heart. Within the chamber, the catheter isextended past a distal end of the guiding sheath to expose the mappingassembly. The catheter is maneuvered through movements that includedeflection of a distal portion of the catheter so that the mappingassembly is positioned at the tubular region in the heart chamber. Theability to control the exact position and orientation of the catheterand also the configuration of the mapping assembly is critical andlargely determines how useful the catheter is.

Viewing of the catheter distal tip during a mapping and/or ablationprocedure is a major benefit. In particular, being able to see a shaftof the catheter in relation to the distal tip would allow the operatingphysician to understand catheter orientation in relation to the othercatheters found in the same region or chamber of the heart. U.S. Pat.Nos. 5,391,199, 5,443,489, 6,788,967 and 6,690,963 to Ben-Haim, whoseentire disclosures are incorporated herein by reference, describesystems wherein the coordinates of an intrabody probe are determinedusing one or more field sensors, such as a Hall effect device, coils, orother antennae carried on the probe. Such systems are used forgenerating three-dimensional location information regarding a medicalprobe or catheter. Preferably, a sensor coil is placed in the catheterand generates signals in response to externally applied magnetic fields.The magnetic fields are generated by three radiator coils, fixed to anexternal reference frame in known, mutually spaced locations. Theamplitudes of the signals generated in response to each of the radiatorcoil fields are detected and used to compute the location of the sensorcoil. Each radiator coil is preferably driven by driver circuitry togenerate a field at a known frequency, distinct from that of otherradiator coils, so that the signals generated by the sensor coil may beseparated by frequency into components corresponding to the differentradiator coils.

It is known to provide the three radiator coils in a biosensor that iscarried in a distal tip section of a catheter. Where the catheter has adistal tip with a 2-dimensional or 3-dimensional flexible configurationwith shape-memory, the biosensor is typically carried proximally of theconfiguration for a number of reasons, including the fragile nature ofthe biosensor and the lack of space in the configuration. However,because the biosensor is not carried on the configuration, a certainamount of human guesswork and/or proximation by the mapping andlocalization system is applied to determine the location and position ofthe configuration.

Accordingly, a desire exists for a catheter that can provide moreaccurate signals of the location of its distal end, especially where thedistal end includes a 2- or 3-dimensional configuration withshape-memory.

SUMMARY OF THE INVENTION

The present invention is directed to a catheter with improved positionand/or location sensing with the use of single axis sensors that aremounted directly on a length or portion of the catheter whoseposition/location is of interest. The magnetic based, single axissensors are provided on a single axis sensor (SAS) assembly, which canbe linear or nonlinear as needed. A catheter of the present inventionthus includes a catheter body and a distal member of a particular 2D or3D configuration that is provided by a support member on which at leastone, if not at least three single axis sensors are mounted seriallyalong the length of the support member.

In one embodiment, the magnetic-based sensor assembly including at leastone coil member that is wrapped on the support member, wherein the coilmember is connected via a joint region to a respective cable memberadapted to transmit a signal providing location information from thecoil member to a mapping and localization system. The joint regionadvantageously provides strain relief adaptations to the at least onecoil member and the respective cable member from detaching. In a moredetailed embodiment, the support member can be tubing, such as polyimidetubing, or a shape-memory member, such as a nitinol member. Also, aprotective tubing is provided over the assembly to encapsulate thesingle axis sensor. Space under the tubing is filled with epoxy or othersuitable materials to fix the components under the tubing. Endcaps ateach end of the tubing may also be formed with epoxy or other suitablematerials.

Where the SAS assembly is linear, it is suitable for use in a lumen ofan intermediate deflection section of the catheter for improved mappingand location sensing of the generally linear structure of theintermediate deflection section. Where the SAS assembly is nonlinear, itis suitable for use in a “lasso” assembly for improved mapping andlocation sensing of the generally non-linear structure of the lassoassembly.

Where the SAS assembly includes multiple single axis sensor arrangedserially a predetermine distance from each other along the supportmember, a nonconductive tubing is provided under the coil sensor of themore proximal sensor(s) so that cable(s)s from the more distal sensor(s)can extend under the tubing for isolation from the coil sensor.

In a more detailed embodiment, strain relief adaptations includeproviding a predetermine amount of slack in coil wire in the jointregion and winding of the cable around the support member to betteranchor the joint region against damage and detachment. Cables from eachsensor are wound more loosely along the length of the support member,the plurality of cables increasing with the windings passing each sensortoward the proximal end of the support member. A heat shrink tubing isprovided along generally the entire length of the support member, overeach sensor, to protect, isolate and seal the sensors.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bebetter understood by reference to the following detailed descriptionwhen considered in conjunction with the accompanying drawings. It isunderstood that selected structures and features have not been shown incertain drawings so as to provide better viewing of the remainingstructures and features.

FIG. 1 is a top plan view of one embodiment of the catheter of thepresent invention.

FIG. 2A is a side cross-sectional view of an embodiment of a junction ofa catheter body and an intermediate section, taken along a firstdiameter.

FIG. 2B is a side cross-sectional view of the junction of FIG. 2 a ,taken along a second diameter generally perpendicular to the firstdiameter.

FIG. 3A is a side cross-sectional view of the embodiment of a junctionof the intermediate section and a distal tip section, along a firstdiameter.

FIG. 3B is a side cross-sectional view of the junction of FIG. 3A, takenalong a second diameter generally perpendicular to the first diameter.

FIG. 4 is a longitudinal cross-sectional view of the intermediatesection of FIG. 3A, taken along line 4-4.

FIG. 5 is a side cross-sectional view of an embodiment of a distal tipsection of the catheter of the present invention.

FIG. 6 is a side view of an embodiment of a linear single axis sensorassembly in accordance with the present invention.

FIG. 7 is a top plan view of another embodiment of the catheter of thepresent invention.

FIG. 8A is a side cross-sectional view of an embodiment of a junction ofa catheter body and an intermediate section, taken along a firstdiameter.

FIG. 8B is a side cross-sectional view of the junction of FIG. 8A, takenalong a second diameter generally perpendicular to the first diameter.

FIG. 9 is a side view of a distal portion of the catheter of FIG. 7 ,including an intermediate section and a mapping assembly.

FIG. 10 is a longitudinal cross-sectional view of the intermediatesection of FIG. 9 , taken along line 10-10.

FIG. 11 is a schematic view of the mapping assembly showing onearrangement of the ring electrodes.

FIG. 12 is a longitudinal cross-sectional view of the mapping assemblyof FIG. 9 , taken along line 12-12.

FIG. 13 is a side cross-sectional view of an embodiment of a distal endof the mapping assembly of FIG. 9 .

FIG. 14A is a side cross-sectional view of an embodiment of a junctionbetween the intermediate section and the mapping assembly, taken along afirst diameter.

FIG. 14B is a side cross-sectional view of the junction between theintermediate section and the mapping assembly, taken along a seconddiameter generally perpendicular to the first diameter.

FIG. 15 is a top plan view of an embodiment of a control handle housinghalf including an embodiment of a deflection control assembly.

FIG. 16 is a top perspective view of an embodiment of a rocker member ofa deflection control assembly.

FIG. 17 is a bottom perspective view of an embodiment of a rockermember.

FIG. 18 is a partial perspective view of a portion of an embodiment of adeflection arm and a tension control member mounted on a control handle.

FIG. 19 is a side view of an embodiment of a pulley of a deflectioncontrol assembly.

FIGS. 20A-20C are schematics of an embodiment of the deflection controlassembly in neutral and rotated configurations.

FIG. 21 is a longitudinal cross section of an embodiment of thedeflection control assembly and tension control assembly mounted on acontrol handle.

FIG. 21A is a detailed view of a portion of FIG. 21 , including anembodiment of a retaining nut and a tension screw.

FIG. 22 is a partial perspective view of an embodiment of a firstcontrol handle housing half.

FIG. 23 is a perspective view of an embodiment of a deflection arm.

FIG. 24 is a perspective view of an embodiment of a tension controldial.

FIG. 25 is a perspective view of an embodiment of a locking plate.

FIG. 26 is a partial perspective view of a portion of an embodiment of acontrol handle.

FIG. 27 is a partial perspective view of a portion of an embodiment of asecond control handle housing half and a retaining nut, the secondcontrol housing half adapted to oppose the first control handle housinghalf.

FIG. 28 is a perspective view of the tension control dial of FIG. 24 andlocking plate of FIG. 25 as assembled.

FIG. 29 is a perspective view of an embodiment of a rotational controlassembly.

FIG. 30 is an exploded perspective view of the rotational controlassembly of FIG. 29 .

FIG. 31 is a side view of an embodiment of a distal single axis sensorof a nonlinear SAS assembly in accordance with the present invention.

FIG. 32 is a side view of an embodiment of a mid single axis sensor of anonlinear SAS assembly in accordance with the present invention.

FIG. 33 is a side view of an embodiment of a proximal single axis sensorof a nonlinear SAS assembly in accordance with the present invention.

FIG. 34 is a top plan view of an embodiment of a nonlinear SAS assemblyin accordance with the present invention.

FIG. 35 is a side view of an embodiment of a proximal single axis sensorof a nonlinear SAS assembly in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1 , the present invention is directed to a catheter 10with at least one single axis sensor, if not three or more single axissensors, mounted on a distal end section 15 that is distal of at least acatheter body 12 if not also an intermediate deflectable section 14. Inthe illustrated embodiment, the distal end section 15 includes a tipelectrode 17. At the proximal end of the catheter body 12 is amulti-functional control handle 16 with mechanisms that are manipulatedby a user to accomplish, for example, bi-directional deflection of theintermediate section 14.

With reference to FIGS. 2A and 2B, the catheter body 12 comprises asingle, central or axial lumen 18. The catheter body 12 is flexible,i.e., bendable, but substantially non-compressible along its length. Thecatheter body 12 may be of any suitable construction and made of anysuitable material. A suitable construction comprises an outer wall 22made of a polyurethane or nylon. The outer wall 22 comprises an imbeddedbraided mesh of stainless steel or the like to increase torsionalstiffness of the catheter body 12 so that, when the control handle 16 isrotated, the tip section of the catheter 10 will rotate in acorresponding manner. A single lumen catheter body 12 can be preferredover a multi-lumen body because the single lumen 18 body can permitbetter tip control when rotating the catheter 10. The single lumen 18permits the components passing therethrough to float freely within thecatheter body. If such components were restricted within multiplelumens, they can build up energy when the handle 16 is rotated,resulting in the catheter body 12 having a tendency to rotate back if,for example, the handle is released, or if bent around a curve, to flipover, either for which are undesirable performance characteristics.

The outer diameter of the catheter body 12 is not critical, but ispreferably no more than about 8 French. Likewise the thickness of theouter wall 22 is not critical. The inner surface of the outer wall 22 islined with a stiffening tube 20, which can be made of any suitablematerial, e.g., polyimide. The stiffening tube 20 is held in placerelative to the outer wall 22 at the proximal end of the catheter body12. A first glue joint 23 is made between the distal ends of thestiffening tube 20 and the outer wall 22 by a fast drying glue, e.g.Super Glue®. Thereafter a second glue joint 26 is formed between theproximal ends of the stiffening tube 20 and outer wall 22 using a slowerdrying but stronger glue, e.g., polyurethane.

The stiffening tube, along with the braided outer wall 22, providesimproved torsional stability while at the same time minimizing the wallthickness of the catheter, thus maximizing the diameter of the singlelumen. The outer diameter of the stiffening tube 20 is about the same asor slightly smaller than the inner diameter of the outer wall 22.Polyimide tubing is suitable because it may be very thin walled whilestill providing very good stiffness. This maximizes the diameter of thecentral lumen 18 without sacrificing strength and stiffness. Polyimidematerial is typically not used for stiffening tubes because of itstendency to kink when bent. However, it has been found that, incombination with an outer wall 22 of polyurethane, nylon or othersimilar material, particularly having a stainless steel braided mesh,the tendency for the polyimide stiffening tube 20 to kink when bent isessentially eliminated with respect to the applications for which thecatheter is used.

In one embodiment, the outer wall 22 has an outer diameter of about0.092 inch and an inner diameter of about 0.063 inch and the polyimidestiffening tube 20 has an outer diameter of about 0.0615 inch and aninner diameter of about 0.052 inch.

As shown in FIGS. 2A, 2B and 4 , the intermediate section 14 comprises ashorter section of tubing 19 with multiple off-axis lumens, for example,first, second, third and fourth lumens 30, 31, 32 and 33. The tubing 19is made of a suitable non-toxic material which is preferably moreflexible than the catheter body 12. A suitable material for the tubing19 is braided polyurethane, i.e., polyurethane with an embedded mesh ofbraided stainless steel or the like. The outer diameter of theintermediate section 14, like that of the catheter body 12, ispreferably no greater than about 8 French. The size of the lumens is notcritical. In one embodiment, the intermediate section has an outerdiameter of about 7 French (0.092 inch) and the lumens are generallyabout the same size, having a diameter of about 0.022 inch, or selectedlumens can have a slightly larger diameter of about 0.036 inch.

A means for attaching the catheter body 12 to the intermediate section14 is illustrated in FIGS. 2A and 2B. The proximal end of theintermediate section 14 comprises an inner counter bore 24 that receivesthe outer surface of the polyimide stiffener 20. The intermediatesection 14 and catheter body 12 are attached by glue 29 or the like.

As shown in FIGS. 2A and 2B, extending through the single lumen 18 ofthe catheter body 12 are various components, for example, lead wires andmultiple puller members, and any other wires or cables. Longitudinalmovement of the puller members relative to the catheter body 12 enableuser control of various parts of the catheter via the control handle. Inone embodiment, the puller members include a pair of deflection pullermembers 42 for bi-directionally deflecting the intermediate section 14.

A deflection puller member 42 extends through the central lumen 18 ofthe catheter body 12 and into the second lumen 31 of the intermediatesection 14. Another deflection puller member 42 extends through thecentral lumen 18 and into the fourth lumen 33 of the intermediatesection 14. The distal ends of the deflection puller members 42 areanchored to the wall of the tubing 19 near the distal end of theintermediate section 14 by means of T-anchors 83 (FIG. 3B). In theintermediate section 14, each deflection puller members 42 extendsthrough a plastic, e.g., Teflon®, sheath 81, which prevents thedeflection puller members 42 from cutting into the wall of the tubing 19of the intermediate section 14 when the intermediate section 14 isdeflected.

As shown in FIG. 2A, compression coils 56 in surrounding relation to thedeflection puller members 42 extend from the proximal end of thecatheter body 12 to the proximal end of the intermediate section 14. Thecompression coils 56 are made of any suitable metal, e.g., stainlesssteel. The compression coils 56 are tightly wound on itself to provideflexibility, i.e., bending, but to resist compression. The innerdiameter of the compression coils 56 is preferably slightly larger thanthe diameter of the puller wires 42. For example, when a puller member42 has a diameter of about 0.007 inches, the compression coil 56preferably has an inner diameter of about 0.008 inches. The Teflon®.coating on the puller member 42 allows them to slide freely within thecompression coils. The outer surface of the compression coils can becovered by a flexible, non-conductive sheath to prevent contact betweenthe compression coils and other components, such as lead wires andcables, etc. A non-conductive sheath can be made of polyimide tubing.

The compression coils 56 are anchored at their proximal ends to theproximal end of the stiffening tube 20 in the catheter body 12 by gluejoint 50 (FIG. 2B) and at its distal end near the proximal end of theintermediate section 14 in the second lumen 31 and fourth lumen 33 byglue joints 51 (FIG. 2B).

As illustrated in FIGS. 3A, 3B and 5 , the tip section 15 includes thetip electrode 17 which may be connected to the tubing 22 of theintermediate section 14 by means of a single lumen connector tubing 23.The connector tubing provides transition space for the variouscomponents extending from the tubing 22 to reorient themselves as neededfor anchoring in the tip electrode 17. To that end, a distal surface ofthe tip electrode is provided with blind holes. In the disclosedembodiment, blind hole 61 is provided to receive a distal end of the tipelectrode lead wire 40, blind hole 63 to receive a distal end of thethermocouple wires 43 and 44. Irrigation passage 66 is also formed inthe tip electrode to receive a distal end of the irrigation tubing 35.The passage 66 is in communication with transverse branches 67 and fluidports 69 allowing fluid delivered through the tubing 35 to pass tooutside of the tip electrode.

In accordance with a feature of the present invention, first lumen 30 ofthe intermediate deflection section 14 carries a linear single axissensor (“SAS”) assembly 300, a detailed embodiment of which is shown inFIG. 6 . The SAS assembly carries at least one, if not three single axissensors 301, for sensing location and/or position of a length of theintermediate deflection section 14. The sensors enable any portion ofthe catheter carrying the SAS assembly to be viewed under mappingsystems manufactured and sold by Biosense Webster, Inc., including theCARTO, CARTO XP and NOGA mapping systems.

The linear SAS assembly 300 includes a generally linear support memberof a predetermined length, for example, a relative stiff, triple walledpolyimide tubing 305 of a predetermined length with a durometer rangingbetween about 80 and about 83, and more preferably between about 81 andabout 82. The tubing has a single lumen 310 and carries the single axissensors 301 serially along its length. Where there are three single axissensors, the assembly carries a distal sensor 301A, a mid sensor 301Band a proximal sensor 301C. Each sensor includes a conducting member303, e.g., a very fine small gauge wire, that is wound repeatedly aroundthe tubing 305 to form a sensing coil as understood by one of ordinaryskill in the art. A distal portion 306 of the wire extends proximallyunder the coil. The distal portion 306 and a proximal portion 307 of thewire both extend proximally past the coil and are each joined, e.g., bysoldering, to a respective exposed distal end of a wire encased in adual side-by-side wire cable 308 at a joint region located just proximalof the coil 303. Each joint region includes a strain relief adaption.The adaptation includes each end of the wire being provided with apredetermined amount of slack S distal of the soldering so as tominimize the risk of breakage and detachment in the joint region.Moreover, the cable 308 also provides strain relief for the sensoragainst breakage. In the disclosed embodiment, the strain reliefincludes multiple windings 309 of the cable, for example, about 720degrees, generally transversely, around the tubing to anchor thesoldered joints between the coil wire 303 and the cable 308. Proximal ofthe strain relief adaption, the cable 308 enters the central lumen 310of the tubing 305 via an aperture 312 form in the wall of the tubing305, where it extends proximally toward the control handle and beyondtoward the mapping and localization system for processing signals sensedby the sensors 301A, 301B, 301C. The assembly allows for the sensor toretain its shape while protecting the connection to each sensor. Thetubing 305 physically and electrically isolates the wire and cable fromother components in the catheter. The tubing also protects and shieldsthe wire and cable from damage during construction and use of thecatheter. It also functions as a scaffold to the sensor to retain itsshape.

As mentioned, the disclosed embodiment provides three single axissensors, each of has a similar structure as described above. Proximalthe proximal sensor, cables 308 extend proximally in parallel throughthe central lumen 310 toward the control handle and beyond toward themapping and localization system. To protect the fragile and delicatenature of the single axis sensors and the soldered joints with thecables, a heat shrink sleeve 315 (shown in a side cross-sectional viewin FIG. 6 ) is included with assembly 300 covering each of the coils,the soldered joints and the strain relief adaptations. Epoxy, UV glueand/or similar material 317 (also shown in a side cross-sectional viewin FIG. 6 ) is injected into the heat shrink sleeve 317 to providefurther support to the SAS assembly 300 by potting and fixing the coilsand the strain relief adaptations onto the tubing and in the heat shrinksleeve. The epoxy provides an added degree of rigidity to the SASassembly 300 as further protection against breakage and detachment ofthe coil wires and the sensor cables but does not adversely affectdeflection of the intermediate section 14.

Each single axis sensor 301 of the linear SAS assembly 300 thus includesa respective coil 301, a respective dual-wire cable 308, respectivestrain relief adaptations including the wire slack S and the cablewindings 309, and respective solder joints electronically coupling thecoil and the cable. With reference to the embodiments of FIGS. 2B and3A, distal and proximal ends 318, 319 of the support member 305 areanchored at or near the distal and proximal end of the tubing 19 of theintermediate deflectable section 14. The cables 308A, 308B, 308C extendproximally from the assembly 300 through the lumen 30 of the tubing ofthe intermediate section 14 and the central lumen 18 of the catheterbody toward the mapping and localization system. A protective,nonconductive sheath 313 can be provided for the cables.

In manufacturing the linear SAS assembly 300, the distal sensor coil303A is wound on the tubing 305, followed by soldering of the ends 306A,307A to the spliced distal end of cable 308A which is then fed into thecentral lumen 310 via the aperture 312A formed by perforation with apreheated needle or in any similar method. At predetermined distanceproximal of the distal sensor coil 303A, the mid-sensor coil 303B iswound on the tubing 305 followed by soldering of ends 306B, 306B tospliced distal end of cable which 308B is then fed into the centrallumen 310 via the aperture 312B to extend along with the cable 308Atoward the mapping and localization system. At a predetermined distanceproximal of the mid sensor coil 303B, the proximal coil 303C is wound onthe tubing 305 followed by soldering of ends 306C, 307C to spliceddistal end of cable 308C which is fed into the central lumen 310 viaaperture 312C to extend along with the cables 308A, 308B toward themapping and localization system. The heat shrink sleeve 315 is placedover the tubing and all the components to protect and seal the assembly300. Epoxy 317 is then injected into as a filler into the space betweenthe sleeve and the components. The assembly 300 is then inserted intothe lumen 30 of the tubing 19 of the intermediate section 14 (or anyother suitable portion of the catheter) with the cables 308A, 308B, 308Cextending through the lumen 30 of the intermediate section 14 and thencentral lumen 18 of the catheter body 12. The assembly 300 issufficiently flexible to allow deflection of the intermediate section 14as needed or appropriate.

In an alternate embodiment as shown in FIG. 7 , the distal section 15distal of the intermediate shaft 14 is 3-D configuration, for example, amapping assembly 27.

A disclosed embodiment of the catheter body 12 and the intermediatedeflection section 14 are illustrated in FIGS. 8A, 8B and 10 .Construction and structure are similar to the above-described embodimentand thus the above description similarly applies. However, differencesinclude adaptations for accommodating the mapping assembly 17, asillustrated and understood by one of ordinary skill in the art.

With reference to FIG. 9 , the mapping assembly 27 comprises a generallystraight proximal region 38 and a generally circular main region 39. Theproximal region 38 is mounted on the intermediate section 14, asdescribed in more detail below, so that it is generally a linearextension of the intermediate section 14. In one embodiment, theproximal region 38 has an exposed length, e.g., not contained within theintermediate section 14, ranging from about 3 mm to about 12 mm, morepreferably about 3 mm to about 8 mm, still more preferably about 5 mm,but can vary as desired. An “elbow” 37 is formed between the proximalregion 38 and the generally circular main region to accommodate theangular transition therebetween.

The generally circular main region 39 is generally traverse, if not alsoperpendicular, to the catheter body 12. The generally circular mainregion 39 can form a flat circle or can be very slightly helical. In oneembodiment, the main region 39 has an outer diameter ranging from about10 mm to about 25 mm, more preferably about 12 mm to about 20 mm. Thegenerally circular main region 39 can curve in a clockwise direction ora counterclockwise direction. As shown in FIGS. 11, 12, 13, 14A and 14B,the mapping assembly 17 is formed of a non-conductive cover or tubing 52which can have any cross-sectional shape as desired. The non-conductivecover 52 can be made of any suitable material, and is preferably made ofa biocompatible plastic such as polyurethane or PEBAX. Thenon-conductive cover 52 can be pre-formed into the desired generallycircular shape of the generally circular main region 39. Alternatively,the shape of the generally circular main region 39 can be defined by awire or other component extending through the non-conductive cover 52.

In the depicted embodiment, a pre-formed support member 54 extendsthrough the non-conductive cover 52 to define the shape of the generallycircular main region 39. The support member 54 is made of a materialhaving shape-memory, i.e., that can be straightened or bent out of itsoriginal shape upon exertion of a force and is capable of substantiallyreturning to its original shape upon removal of the force. On suitablematerial for the support member 54 is a nickel/titanium alloy. Suchalloys typically comprise about 55% nickel and 45% titanium, but maycomprise from about 54% to about 57% nickel with the balance beingtitanium. A suitable nickel/titanium alloy is Nitinol, which hasexcellent shape memory, together with ductility, strength, corrosionresistance, electrical resistivity and temperature stability.

The support member 54 supports a nonlinear SAS assembly 400 inaccordance with a feature of the present invention, an embodiment ofwhich is illustrated in FIGS. 34 and 35 . The non-linear SAS assembly400 carries at least one, if not three or more single axis sensors 401A,401B, 401C, for sensing location and/or position of the mapping assembly17. The sensors enable the mapping assembly carrying the non-linear SASassembly to be viewed under mapping systems manufactured and sold byBiosense Webster, Inc., including the CARTO, CARTO XP and NOGA mappingsystems.

The disclosed embodiment includes three single-axis sensors positionedat equi-distance from each other along the generally circular mainregion 39. The proximal sensor 401C is immediately distal of the elbow37. A mid-sensor 401B is about 120 degrees from the proximal sensor. Adistal sensor 401A is about 120 degrees from the mid-sensor.

As shown in the embodiment of FIG. 31 , the distal sensor 401A includesa conducting member 403A, e.g., a wire, that is wound repeatedly arounda predetermined length of a nonconductive tubing 404 surrounding thesupport member 54 to form a sensing coil as understood by one ofordinary skill in the art. A distal section 406A of the wire extendsproximally under the coil 403A. The distal section 406A and a proximalsection 407A of the wire both extend proximally past the coil 403A andare each joined, e.g., by wrapping and/or soldering, to a respectiveexposed distal end of a wire encased in a respective dual side-by-sidewire cable 408A at a joint region located just proximal of the coil 403Aand the tubing 404A. In the joint region are strain relief adaptations,including the provision at each end of the wire a predetermined amountof slack S proximal in the joint region so as to minimize the risk ofbreakage and detachment at the soldering joint. Moreover, the cable 408Aincludes multiple windings of the cable 409A, generally transverse, forexample, at least two consecutive 720 degrees, around the support member54 to anchor the soldered joints between the coil wire and the cable. Aprotective tubing 416, for example, of polyimide, of sufficient lengthis placed over the tubing, coil, soldering joints and the most distalstrain relief 720 degree winding for sensor 403A. Epoxy, UV glue and/orsimilar material 417 is injected into the tubing to fill the spacebetween the tubing and the components of the sensor, with excess epoxyextending distally and proximally of the tubing to form end caps 419Aaround the encapsulated single axis sensor. The proximal end cap maycover the strain relief 720 degree winding proximal of the most distalstrain relief 720 degree winding. The epoxy provides further support toeach encapsulated single axis sensor by potting and fixing therespective coils and the strain reliefs onto the tubing and in the heatshrink sleeve. The epoxy provides an added degree of rigidity to theencapsulated single axis sensor as further protection against breakageand detachment of the coil wires and the sensor cable. Proximal theencapsulated single axis sensor are additional strain relief 720 degreewindings 420A of the cable. Further proximal are looser (e.g., diagonal)windings 422A of the cable around the support member 54.

The mid single axis sensor 403B and the proximal single axis sensor 403Aare formed in a similar manner with a similar structure. However, asshown in the embodiments of FIGS. 31 and 32 , the dual wire cable 408from the more distal single axis sensor(s) extend under thenon-conductive tubing 404 and thus are insulated and isolated from eachsensor coil 403. Proximal of the coils, the cables 408 are jointly woundtransversely and diagonally as desired or appropriate proximally towardthe elbow 37 of the mapping assembly 17.

Extending over all three single axis sensors between a locationimmediately distal of the distal single axis sensor 401A and proximal ofthe elbow 37 but distal of the proximal end of the support member 54 isan outer non-conductive heat shrink sleeve 430.

In manufacturing the non-linear SAS assembly 400, the distalencapsulated SAS 401A is formed, followed by the mid encapsulated SAS401B, and then the proximal SAS. 401C The outer heat shrink sleeve 430is then placed over all three SASes. The assembly 400 is sufficientlyflexible to allow expansion or contraction of the mapping assembly 17 asneeded or appropriate and the assembly 400 is ready for mounting of ringelectrodes 26, as described below.

The cables 408A, 408B, and 408C extend proximally from the assembly 400through the tubing 52 of the assembly 17 exiting the proximal region 38,through the lumen 32 of the intermediate section 14 and through thecentral lumen 18 of the catheter body 12. The cables 408A, 408B and 408Ccan extend through a protective, nonconductive sheath 413.

The assembly 400 is inserted into the nonconductive cover 52 to extendtherethrough. A series of ring electrodes 26 are mounted on thenon-conductive cover 52 forming the generally circular main region 39 ofthe mapping assembly 17, as shown in FIG. 11 . The ring electrodes 26can be made of any suitable solid conductive material, such as platinumor gold, or a combination of platinum and iridium, and mounted onto thenon-conductive cover 52 with glue or the like. Alternatively, the ringelectrodes 26 can be formed by coating the non-conductive cover 52 withan electrically conducting material, like platinum, gold and/or iridium.The coating can be applied using sputtering, ion beam deposition or anequivalent technique. A suitable mapping assembly is described in U.S.Pat. No. 7,274,957, the entire disclosure of which is herebyincorporated by reference. If desired, additional electrodes (not shown)could be mounted along the intermediate section 14 and/or the generallystraight proximal section 38.

The contraction puller member 35, for example, a contraction pullerwire, is provided to contract the generally circular main region 39 tothereby change or reduce its diameter, for example, when mapping orablating circular or tubular regions of the heart. The contraction wire35 has a proximal end anchored in the control handle 16, which is usedto manipulate the contraction wire as described further below. Thecontraction wire 35 extends through the central lumen 18 of the catheterbody 12, through the third lumen 32 of the intermediate section 14 andinto the non-conductive cover 52 of the mapping assembly 17. The portionof the contraction wire 35 extending through the non-conductive cover 52is positioned on the side of the generally circular main region 39closer to the center of the generally circular main region, as bestshown in FIG. 6 . The center of the generally circular main regionrefers to the center of the circle formed by the generally circular mainregion. With this arrangement, contraction of the generally circularmain region 39 is dramatically improved over arrangements where theposition of the contraction wire 35 is not so controlled.

As shown in FIGS. 11 and 12 , within the mapping assembly 17, thecontraction wire 35 extends through a plastic tube 55. In oneembodiment, the plastic tube 55 comprise three layers, including aninner layer of polyimide over which a braided layer is formed, thebraided layer comprising a braided stainless steel mesh or the like, asis generally known in the art. The braided layer enhances the strengthof the plastic tube 55, reducing the tendency for contraction wire 35 tostraighten the preformed curve of the mapping assembly 17. A thinplastic layer of polytetrafluoroethylene is provided over the braidedlayer to protect the braided layer from getting tangled with the leadwires 40 within the non-conductive cover 52. The plastic tube 55 has aproximal end anchored to the distal end of the intermediate section 14in the third lumen 32 by glue or the like (FIG. 14A). The support member54 extends through the plastic tube 55 with the contraction wire 35(FIG. 14A). The distal ends of the support member 54 and the contractionwire 35 are soldered or otherwise attached to a small stainless steeltube 53 (FIG. 13 ). With this arrangement, the relative positions of thecontraction wire 35 and the support member 54 can be controlled so thatthe contraction wire can be positioned on the side of the generallycircular region 39 closer to the center of the generally circular region39, as described above. The contraction wire 35 on the inside of thecurve pulls the support member 54 to the inside of the curve, enhancingcontraction of the generally circular region 39. Further, when theplastic tube 55 includes a braided layer, it keeps the contraction wire35 from tearing through the non-conductive cover 52.

A third compression coil 46 is situated within the catheter body 12 andintermediate section shaft 14 in surrounding relation to the contractionwire 35 (FIG. 8A). The third compression coil 46 extends from theproximal end of the catheter body 12 to near the distal end of the thirdlumen 32 of the intermediate section 14. The third compression coil 46is made of any suitable metal, e.g., stainless steel, and is tightlywound on itself to provide flexibility, i.e., bending, but to resistcompression. The inner diameter of the third compression coil 46 ispreferably slightly larger than the diameter of the contraction wire 35.The outer surface of the compression coil 46 is covered by a flexible,non-conductive sheath 68, e.g., made of polyimide tubing. The thirdcompression coil 46 can be formed of a wire having a square orrectangular cross-sectional area, which makes it less compressible thana compression coil formed from a wire having a circular cross-sectionalarea. As a result, the third compression coil 46 keeps the catheter body12, and particularly the intermediate section 14, from deflecting whenthe contraction wire 35 is manipulated to contract the mapping assembly17 as it absorbs more of the compression.

The third compression coil 46 is anchored at its proximal end to theouter wall 20 of the catheter body 12 by the proximal glue joint 50 andto the intermediate section 14 by distal glue joint 72.

It is understood that glue joints throughout the catheter 10 maycomprise polyurethane glue or the like. The glue may be applied by meansof a syringe or the like through a hole made in the tubing walls. Such ahole may be formed, for example, by a needle or the like that puncturesthe tubing walls where the needle is heated sufficiently to form apermanent hole. The glue is then introduced through the hole to wickaround the component(s) within the tubing to form a glue joint about theentire circumference of the component(s).

In the depicted embodiment of FIG. 13 , the distal end of the mappingassembly 17 is sealed closed with a dome 51 of polyurethane glue or thelike. A short ring 56, made of metal or plastic, and e.g., polyamide, ismounted within the distal end of the non-conductive cover 52. The shortring 56 prevents the distal end of the non-conductive cover 52 fromcollapsing, there by maintaining the diameter of the non-conductivecover at its distal end.

At the junction of the intermediate section 14 and the mapping assembly17 as shown in FIGS. 14A and 14B, the non-conductive cover 52 isattached to the intermediate section 14 by glue or the like. The plastictube 55 has its proximal end inserted and glued in the distal end of theintermediate section 14. The glue (not shown) from the plastic tube 55can further serve to anchor the distal end of the third compression coil46 in place within the third lumen 32. The support member 54 extendsfrom the third lumen 32 into the plastic tube 55 within thenon-conductive cover 52. The proximal end of the support member 54terminates a short distance proximally from the distal end of the thirdlumen 32, approximately about 5 mm, so as not to adversely affect theability of the intermediate section 14 to deflect. However, if desired,the proximal end of the support member 54 can extend proximally furtherinto the intermediate section 14 and/or the catheter body 12.

The lead wires 40 attached to the ring electrodes 26 extend through thefirst lumen 30 of the intermediate section 14 (FIG. 8A), through thecentral lumen 18 of the catheter body 12, through the control handle 16,and terminate at their proximal end in a connector (not shown) which isconnected to an appropriate monitor or other device for receiving anddisplaying the information received from the ring electrodes 26. Theportion of the lead wires 40 extending through the central lumen 18 ofthe catheter body 12, control handle 16 and proximal end of theintermediate section 14 is enclosed within a protective sheath 62, whichcan be made of any suitable material, such as polyimide. The protectivesheath 62 is anchored at its distal end to the proximal end of theintermediate section 14 by gluing it in the lead wire lumen 30 withpolyurethane glue or the like to form glue joint 73.

The lead wires 40 are attached to the ring electrode 26 by anyconventional technique. In one embodiment, each ring electrode 26 ismounted by first forming a hole in the non-conductive cover 52. Anelectrode lead wire 40 is fed through the hole, and the ring electrode26 is welded in place over the lead wire and non-conductive cover 52.

With reference to FIG. 7 , the control handle 16 comprises a generallyelongated handle housing, which can be made of any suitable rigidmaterial, such as plastic configured through a suitable molding process.In the illustrated embodiment, the housing includes two opposing halves16 a and 16 b that generally mirror each other and are joined by glue,sonic welding or other suitable means along a longitudinal peripheralseam 28 around the housing. In the illustrated embodiment, the crosssection of the handle 16 formed by the opposing halves changes along thelength of the handle. A more distal portion 112 has a smaller, generallyrectangular cross section. A mid-portion 114 has a larger, generallyrectangular cross section. A more proximal portion 116 has a generallycircular cross section.

In the illustrated embodiment of FIGS. 1 and 9 , the control handle 16houses components of a deflection control assembly 74 in the mid-portion114. The deflection control assembly includes a deflection member or arm75 that can be directly manipulated by an operator to control deflectionof the intermediate section 14. The deflection arm 75 is rotatable aboutan axis 76 that is generally transverse or perpendicular to thelongitudinal axis of the control handle. The deflection control assembly74 has a rotatable rocker member 78 that acts on the deflection pullermembers 42 to deflect the intermediate section 14.

The rocker member 78 has a length L dimension, a width W dimension and athickness T dimension (FIGS. 10 and 11 ). Along its thickness dimensionT, the rocker member 78 is configured with two opposing annularformations 140 a and 140 b that define a central hole or passage 143that extends through its entire thickness. The central hole 143 isaligned with the rotational axis 76 of the deflection arm 75. Along itslength dimension L, the rocker member 78 also has two smaller holes 146that oppose each other across the central hole 143. In each hole sits apulley 147, for example, a snap bearing (FIG. 12 ), that has arotational axis parallel to the axis 76. Each deflection puller member42 enters the rocker member through slots 148 and a portion is woundaround a respective pulley 147.

As understood by one of ordinary skill in the art, the rocker member 78and the pulleys 147 are arranged such that rotation of the rocker memberin one direction about the axis 76 draws back one puller member 42 todeflect the intermediate section 14 in that direction. With reference toFIGS. 20A-20C, as the rocker member 78 is rotated by means of thedeflection arm (as represented by line 75), the pulleys 147 aredisplaced from a neutral position (FIG. 20A) with one pulley 147 drawinga puller member 42 on one side of the catheter body 12 against itsanchored proximal end for deflecting the intermediate section 14 towardthat side (FIGS. 20A-20C).

Each deflection puller member 42 may comprise multiple segments. Asillustrated in FIG. 9 , each deflection puller member has a distalpuller wire 42 a and a proximal fiber 42 b that are joined or connectedat a location within the control handle 16 distal the rocker member 78.The puller wire 42 a and the tensile fiber 42 b of each deflectionpuller member are connected or secured to each other by a connector 154,e.g., a crimped brass ferrule covered by shrink tubing. Each puller wire42 a extends through the catheter body 12 and the intermediate section14. Each tensile fiber 42 b extends inside the control handle 16. Inthis manner, it is the more flexible tensile fibers 42 b that interactwith the pulleys 147 and undergo repeated bending and straighteningduring deflection operations, as they are less prone to bending stressand fatigue failure.

Each puller wire 42 a is made of any suitable metal, such as stainlesssteel or Nitinol. Preferably each puller wire has a low frictioncoating, such as a coating of Teflon® or the like. Each puller wire hasa diameter preferably ranging from about 0.006 inch to about 0.012 inch.Preferably both of the puller wires have the same diameter. Flat pullerwires may be used in place of round puller wires. Their cross sectionaldimensions should be such that they provide comparable tensile strengthsas round puller wires.

Each tensile fiber 42 b may be of a high modulus fiber material,preferably having an ultimate tensile strength substantially in therange of 412-463 ksi (2480-3200 Mpa) such as High Molecular DensityPolyethylene (e.g., Spectra™ or Dyneema™), a spun para-aramid fiberpolymer (e.g., Kevlar™) or a melt spun liquid crystal polymer fiber rope(e.g., Vectran™), or a high strength ceramic fiber (e.g., Nextel™). Theterm fiber is used herein interchangeably with the term fibers in thatthe tensile fiber may be of a woven or braided construction. In anycase, these materials tend to be flexible, providing suitable durabilitywhen used in wrapped engagement with the pulleys and the like forgreater throw in deflecting the catheter tip. Further, they aresubstantially non-stretching, which increases the responsiveness to themanipulation of the control handle, and nonmagnetic so that theygenerally appear transparent to an MRI. The low density of the materialcauses it to be generally transparent to an x-ray machine. The materialscan also be nonconductive to avoid shorting. Vectran™, for example, hashigh strength, high abrasion resistance, is an electrical insulator,nonmagnetic, is polymeric, and has low elongation under sustainedloading conditions.

In the illustrated embodiment of FIG. 9 , each tensile fiber 42 bextends proximally from the connector 154 toward the rocker member 78where each is wound around a respective pulley 147 and turns about 180degrees to double back toward the distal end of the control handle. Eachproximal end of the tensile fiber 42 b is anchored by an anchor assembly90 that includes a pair or racks 92, a slug 94 and a stop 96. Theproximal end of each tensile fiber 22 b extends between a channel 91defined by the pair of racks 92, and the proximal end of each tensilefiber is encased within a molded member or slug 94 sized to fit in andtranslate in the channel 91. Proximal the slug are the stops 96 that areadjustably positioned in a selected location along the racks 92, forexample, by means of interlocking teeth 98 formed in the racks and thestops to releasably lock in the selected position against movement. Thestops 96 are formed so that each respective tensile fiber 42 b can slidethrough or below them while blocking the slugs 94 from moving proximallypast them. Accordingly, the stops 96 limit the proximal movement of theslugs 94 and anchor the proximal ends of the tensile fibers 42 b toeffectuate deflection when each is drawn proximally by the deflectioncontrol assembly 74. During assembly of the control handle 16, beforethe two housing halves 16 a, 16 b are joined, the stops 96 areselectively positioned between the racks 92 to achieve a desirabletension in each tensile member. The interlocking teeth 98 of the racks92 and stops 96 allow for fine adjustments in setting the tension.

The construction and assembly of the deflection control assembly 74including the deflection arm 75 and a tension adjustment member 101 onthe control handle 16 are described as follows. With reference to FIGS.14A and 14B, the rocker member 78 of the assembly 74 is situated betweenthe two halves 16 a and 16 b of the control handle 16, with each of itsannular formations 140 a and 140 b extending respectively through anopening 120 a, 120 b formed in the distal portion 114 of each housinghalf 16 a and 16 b.

The annular formation 140 a has recesses 160 (FIG. 10 ) exposed throughthe opening 120 a (FIG. 15 ) that receive protrusions 152 projectingfrom a facing surface 154 of the deflection arm 75 (FIG. 16 ) torotationally couple the deflection arm 75 and the rocker member 78. Theprotrusions 152 can snap fit into the recesses 160 and/or be secured byadhesives, glue, sonic welding and the like. A central circularprotrusion 156 from the deflection arm 75 fits into the hole 143circumscribed by the annular formation 140 a of the rocker member 78. Asuitable deflection assembly and control handle are described in U.S.application Ser. No. 12/346,834, published as U.S. Publication No.2010/0168827, the entire disclosure of which is hereby incorporated byreference. Another suitable deflection assembly with deflectionsensitivity is described in U.S. application Ser. No. 12/211,728,published as U.S. Publication No. 2010/0069834, the entire disclosure ofwhich is hereby incorporated by reference. Therein, a cam that isresponsive to a deflection sensitivity knob can vary the separationdistance between the two pulleys 147, thereby changing the deflectionsensitivity of the deflection arm.

Opposing the deflection arm 75 is the deflection tension adjustmentmember or dial 101 (FIGS. 17 and 20 ) which is coupled to and indirectlyengaged with the rocker member 78 by various mechanisms and parts andallows an operator to adjust the ease with which the deflection arm 75can be rotated. Mounted primarily on the housing half 16 b, theillustrated embodiment of a tension adjustment assembly 100 includes theadjustment dial 101 (FIG. 17 ), a locking plate 102 (FIG. 18 ), atension cap screw 103, a retaining nut 136 and a washer 119 (see FIGS.14A and 14B). A user rotates the dial 101 to adjust the tightness ortension of the rotational movement of deflection arm 75 by effectivelycompressing or releasing the rocker member 78 against the washer 119(e.g., a Belleville type) and the control handle housing half 16 b.

The dial 101 has a generally circular cross section with acircumferential edge 115 having a friction-inducing surface (FIG. 17 ).A central circular protrusion 105 and a plurality of prongs 106 (FIG. 17) situated along a diameter of the dial project from a surface 104 ofthe dial 101.

The locking plate 102 is sandwiched between the dial 101 and the handlehousing 16 b (FIG. 20 ). The locking plate 102 (FIG. 18 ) has a centrallarger hole 107 and two smaller holes 108, all three of which extendthrough the entire thickness of the locking plate. The two prongs 106 ofthe dial 101 are adapted to be inserted through the smaller holes 108 inthe plate 102 (FIG. 21 ) and received in semi-circular grooves 109 (FIG.19 ) formed in an outer surface of the housing half 16 b. The grooves109 limit the degree of rotation of the dial 101 in clockwise andcounterclockwise directions. The central hole 107 of the plate 102 (FIG.18 ) has different cross-sections that include a larger circularcross-section 107 a and a smaller circular cross-section 107 b. Thelarger circular cross-section 107 a receives a head 112 of a cap screw103, and the smaller circular cross-section 107 b receives a threadedbody 115 of the cap screw 103 (FIG. 14 a ).

The threaded body 115 of the cap screw 103 extending through the centralhole 107 of the locking plate 102 engages the retaining nut 136 situatedin the opening 143 of the rocker member 78. A head 115 of the nut abutsand is anchored against a neck 132 formed in the inner surface of theopening 143 of the rocker member 78. The opening 120 b in the housinghalf 16 b (FIG. 21 ) has a larger cross section 122 and a smaller crosssection 124. The smaller cross section 124 has a polygonal shape whichmatches a polygonal (e.g., hexagonal) end 126 of the nut 136 so that thenut 136 is effectively locked against rotation relative to the housinghandle 16 b.

The central protrusion 105 of the dial 101 (FIG. 17 ) forms a press orinterference fit with the head 112 of the cap screw 103 to createrotational alignment between these two components. The prongs 106 of thedial 101 lock and rotationally couple the dial 101 and the lock plate102, and the cap screw 103 is rotationally coupled to the locking plate102. Coupling of the dial 101 and the locking plate 102 may also beachieved by means of welding the two components together. In that case,the prongs 106 need not protrude from the dial 101 but can insteadextend from the locking plate 102.

Between the polygonal end 126 of the nut 136 and the housing handle 16 bis the washer 119 whose compression against the nut 136 and the housinghandle 16 b is adjustable by the user's rotation of the dial 101 whichtightens or releases the engagement between cap screw 103 and the nut136, thus increasing or decreasing the ease with which the rocker member78 and hence the deflection arm 75 can be rotated.

Components that extend through the control handle, including, forexample, the lead wires 40 and the contraction wire 35 also enter thecontrol handle at the distal end. In the illustrated embodiment of FIG.9 , these components extend along the longitudinal axis of the controlhandle. A protective tubing 152 through which the components extend canbe provided, positioned between the two deflection puller members 42 andthrough a channel 150 form through the width dimension W of the rockermember 78 (FIG. 11 ). Distal and proximal portions of the channel 150have indents, e.g., triangular or wedge-shaped, 151 (FIGS. 9 and 11 ) toallow the rocker member 78 to rotate freely within a predetermined rangeof angles, e.g., about ±45 degrees of the longitudinal axis of thecontrol handle 16, without interference by the tubing 152 and thecomponents therethrough.

Alternatively, the components extending through the control handle, withthe exception of the contraction wire 35, are routed on an off-axis path153 diverging from the deflection puller members 42 at entry into thedistal end of the control handle 16. The components thus extend alongthe periphery of the housing handle, bypassing the rocker member 78.

It is understood that the distance between the distal end of thecompression coils 44 and the distal anchor sites of each deflectionpuller members 42 in the intermediate section 14 determines thecurvature of the intermediate section 14 in the direction of thedeflection puller members. For example, an arrangement wherein the twodeflection puller members 42 are anchored at different distances fromthe distal ends of the compression coils 44 allows a long reach curve ina first plane and a short reach curve in a plane 90 degree from thefirst, i.e., a first curve in one plane generally along the axis of theintermediate section 14 before it is deflected and a second curve distalto the first curve in a plane transverse, and preferably normal to thefirst plane. The high torque characteristic of the catheter intermediatesection 14 reduces the tendency for the deflection in one direction todeform the deflection in the other direction. Suitable deflectioncontrol handles and parts thereof for use with such a catheter aredescribed in U.S. patent application Ser. No. 08/924,611, filed Sep. 5,1997, now U.S. Pat. No. 6,123,699, Ser. No. 09/130,359, filed Aug. 7,1998, now U.S. Pat. No. 6,171,277, and Ser. No. 09/143,426, filed Aug.28, 1998, now U.S. Pat. No. 6,183,463, all of which are incorporated byreference.

For adjusting the mapping assembly 17 by means of a third puller member,e.g., the contraction wire 35, a distal end of the contraction wireextending between the two deflection puller members 42 within thecontrol handle is anchored in the control handle for actuation by meansof a rotational control assembly 200. In the illustrated embodiment ofFIG. 23 , the rotational control assembly 200 includes an outerrotational cam 202, a pulley shaft 204 and a pulley 206 around which thethird puller member 35 is wrapped. The cam 202 closely surrounds theproximal portion 116 of the control handle and as the proximal portion116 has a cylindrical shape, the rotational cam is in a circumferentialrelationship with the proximal portion so that it can rotate about alongitudinal central axis 205 of the proximal portion 116 on an outersurface 208 of the proximal portion and serve as a rotational interfacebetween the user and internal components of the rotational controlassembly 200. In that regard, the outer surface 208 is sufficientlysmooth such that the cam 202 can rotate on it with minimal frictionalforces. A friction-inducing surface can be provided on an outer surfaceof the cam 202 to facilitate manipulation and rotation by the user.

The proximal portion 116 under the cam 202 has two diametricallyopposing guide slots 208 extending axially in a direction parallel tothe longitudinal axis 205 of the proximal portion 116. The cam 202 hason its inner surface two opposing helical tracks or grooves 210extending about the longitudinal axis 205. The helical grooves 210 areconfigured such that any plane perpendicular to the longitudinal axisintersects the grooves along a diameter of the proximal portion 116. Theshaft 204 extends diametrically between the two guide slots 208,traversing the interior of the proximal portion at an angle generallyperpendicular to the longitudinal axis 205. The guide slots 208 aresized so that the shaft 204 can pass through the slots and have each ofits two opposing ends 212 be received in a respective helical groove onthe inner surface of the cam. As such, the length of the shaft isgreater than an outer diameter of the proximal portion 116 but lesserthan an outer diameter of the cam 202. Accordingly, the helical grooves210 are sized to receive the ends 212 and allow the ends to slidetherein.

Mounted on the shaft, for example, at or near a midpoint of the lengthof the shaft, is the pulley 206 on which the third puller member iswrapped. The third puller member which can be any suitable material,including a puller wire or contraction wire, has a proximal end (notshown) that is anchored to the control handle or to any other rigidlymounted component within the control handle, at a location distal of thedistal ends of the guide slots. Longitudinal movement of the contractionwire 35 relative to the catheter body 12 can effectuate, for example,contraction and expansion of the mapping assembly 17.

With reference to embodiment of FIGS. 1, 23 and 24 , the rotationalcontrol assembly 200 is positioned proximal the deflection controlassembly 74, although it is understood that it can be positioned distalthe deflection control assembly 74. In the disclosed embodiment, the cam202 is mounted on the proximal portion 116 of the control handle. Thecam 202 can be formed from as a solid piece that slides onto theproximal portion and is snap-fitted over the two ends 212 of the shaft204. Alternatively, the cam can be formed of two halves that aresnap-fit to each other or joined by glue or sonic welding over the twoends of the shaft.

In operation, the rotational control assembly 200 is manipulated bymeans of the cam 202. As a user holds the control handle 16 and rotatesthe cam with his thumb and forefinger to contract or expand the mappingassembly, the two opposing helical tracks 210 on the inner surface arerotated relative to the proximal portion 116 thereby exerting a force onthe shaft 204 via the ends 212 received in the tracks 210 todiametrically spin about the central longitudinal axis 205 of thecontrol handle. However, because the shaft 204 extends through the guideslots 208 of the proximal portion 116, the guide slots limit the shaftto a translational movement proximally or distally along thelongitudinal axis depending on the direction of rotation of the cam 202as the ends 212 slide in the helical tracks 210. As the shaft 204 movesproximally or distally, the pulley 206 thereon correspondingly movesproximally or distally thereby drawing or releasing the third pullermember 35. Advantageously, the rotational control assembly provides amultiplied linear motion of the third puller member, with greatersensitivity in the amount of motion controlled by the user. In thedisclosed embodiment of FIG. 24 , each helix 210 has a rotation of about540° (360°±180°). However, it is understood that the rotation of eachhelix can range between about 180° to 720° depending on how muchcontraction/deflection and/or how much sensitivity is desired.

Lead wires and other components (e.g., thermocouple wires, cables,irrigation tubing) extending through proximal portion 116 in aprotective tubing so as not to interfere with the interior components ofthe rotational control assembly.

In use, a suitable guiding sheath is inserted into the patient with itsdistal end positioned at a desired mapping location. An example of asuitable guiding sheath for use in connection with the present inventionis the Preface™. Braiding Guiding Sheath, commercially available fromBiosense Webster, Inc. (Irvine, Calif.). The distal end of the sheath isguided into one of the chamber, for example, the atria. A catheter inaccordance with the present invention is fed through the guiding sheathuntil its distal end extends out of the distal end of the guidingsheath. As the catheter is fed through the guiding sheath, the mappingassembly 17 is straightened to fit through the sheath. Once the distalend of the catheter is positioned at the desired mapping location, theguiding sheath is pulled proximally, allowing the deflectableintermediate section 14 and mapping assembly 17 to extend outside thesheath, and the mapping assembly 17 returns to its original shape due tothe shape-memory of the support member 54.

By manipulating and rotating the deflection arm 75 of the deflectioncontrol assembly 74 to deflect the intermediate section 14, the mappingassembly 17 is then inserted into a pulmonary vein or other tubularregion (such as the superior vena cava, or inferior vena cava) so thatthe outer circumference of the generally circular main region 39 of theassembly 17 is in contact with a circumference inside the tubularregion. Turning the deflection arm 75 in one direction deflects theintermediate section 14 to that direction. Turning the deflection 75 inthe opposite direction deflects the intermediate section 14 to thatopposite direction. Tension of the deflection 75 is adjusted bymanipulating and rotating the dial 101. Turning the dial 101 in onedirection increases the tension. Turning the dial 101 in the oppositiondirection decreases the tension. Preferably at least about 50%, morepreferably at least about 70%, and still more preferably at least about80% of the circumference of the generally circular main region is incontact with a circumference inside the tubular region.

The circular arrangement of the electrodes 26 permits measurement of theelectrical activity at that circumference of the tubular structure sothat ectopic beats between the electrodes can be identified. The size ofthe generally circular main region 39 permits measurement of electricalactivity along a diameter of a pulmonary vein or other tubular structureof or near the heart because the circular main region has a diametergenerally corresponding to that of a pulmonary vein or the coronarysinus. By manipulating and rotating the cam 202 of the rotationalassembly 200, the assembly 17, in particular, the generally circularmain region 39, is contracted to fit the pulmonary vein or other tubularstructure.

In accordance with a feature of the present invention, rotational motionof the cam results in linear motion of the shaft and the pulley alongthe central longitudinal axis of the control handle. The shaft ridesalong the helical grooves of the cam as it is rotated. The opposinglinear guide slots of the proximal portion of the control handle ensurethat the shaft maintains its general perpendicular orientation resultingin linear motion of the shaft relative to the proximal portion. As theshaft translates along the longitudinal axis, the pulley is also movedwherein its linear displacement results in twice the linear displacementof the third puller member. In the disclosed embodiment, the contractionwire is drawn proximally by the rotational control assembly to tightenand decrease the diameter of the generally circular region 39 when thecam is turned in one direction. By turning the cam in the oppositiondirection, the contraction wire 35 is released to release the generallycircular region 39 such that it expands its diameter.

The preceding description has been presented with reference to presentlypreferred embodiments of the invention. Workers skilled in the art andtechnology to which this invention pertains will appreciate thatalterations and changes in the described structure may be practicedwithout meaningfully departing from the principal, spirit and scope ofthis invention. Any feature or structure disclosed in one embodiment maybe incorporated in lieu of or in addition to other features of any otherembodiments, as needed or appropriate. It is understood that a featureof the present invention is applicable to multiplying linear motion of apuller wire, contraction wire, or any other object requiring insertion,removal, or tensioning within a medical device, including the disclosedelectrophysiology catheter. As understood by one of ordinary skill inthe art, the drawings are not necessarily to scale. Accordingly, theforegoing description should not be read as pertaining only to theprecise structures described and illustrated in the accompanyingdrawings, but rather should be read consistent with and as support tothe following claims which are to have their fullest and fair scope.

What is claimed is:
 1. A catheter comprising: an elongated body; adistal member distal of the elongated body, the distal member having asupport member and a configuration; a control handle proximal of theelongated body; a magnetic-based sensor assembly including at least oneconducting member comprising a wire having first and second ends, thewire comprising: a coil region that is wrapped around the supportmember; and a joint region adjacent the coil region, the joint regioncomprising: a first connection of the first end of the wire to a cablemember at a first location proximal of the coil region, and a secondconnection of the second end of the wire to the cable member at a secondlocation proximal of the coil region, wherein the second end of the wireextends through the coil region from a distal end of the coil region tothe second location proximal of the coil region, a first strain reliefconstruction comprising a first plurality of windings of the cablemember around the support member proximal of the coil region, and asecond strain relief construction comprising a second plurality ofwindings of the cable member around the support member proximal of thecoil region, the second plurality of windings of the cable member beingspaced from the first plurality of windings of the cable member; whereinthe cable member is adapted to transmit a signal providing locationinformation from the at least one conducting member to a mapping andlocalization system, and wherein the joint region provides strain reliefto the coil region and the cable member from detaching.
 2. The catheterof claim 1, wherein the first end of the wire forms a first amount ofslack in the wire between the proximal end of the coil region and thefirst connection, and/or the second end of the wire forms a secondamount of slack in the wire between the proximal end of the coil regionand the second connection.
 3. The catheter of claim 1, wherein thesecond plurality of windings of the cable member amounts to at least 720degrees of winding around the support member.
 4. The catheter of claim1, wherein the magnetic-based sensor assembly further comprises anonconductive tubing mounted on the support member, the coil region ofthe wire of the at least one conducting member being wrapped on thenonconductive tubing.
 5. The catheter of claim 4, wherein the jointregion is proximal of the nonconductive tubing.
 6. The catheter of claim1, wherein the first plurality of windings of the cable member amountsto at least 720 degrees of winding around the support member.
 7. Thecatheter of claim 6, wherein the second plurality of windings of thecable member amounts to at least 720 degrees of winding around thesupport member.
 8. The catheter of claim 1, wherein the joint regionfurther comprises a third strain relief construction comprising a thirdplurality of windings of the cable member around the support member, thethird plurality of windings of the cable member being spaced from boththe first plurality of windings of the cable member and the secondplurality of windings of the cable member.
 9. The catheter of claim 8,wherein the windings of the third plurality of windings of the cablemember are looser than the windings of the first plurality of windingsof the cable member and the windings of the second plurality of windingsof the cable member.
 10. The catheter of claim 8, wherein the thirdplurality of windings of the cable member comprises diagonal windings.11. The catheter of claim 1, wherein the magnetic-based sensor assemblyfurther comprises a protective tubing over the coil region, joint regionand first strain relief construction.
 12. The catheter of claim 11,wherein the magnetic-based sensor assembly further comprises an epoxy orUV glue occupying a space inside of the protective tubing.
 13. Thecatheter of claim 12, wherein the epoxy or UV glue forms end caps ateach end of the protective tubing.
 14. The catheter of claim 13, whereinone of the end caps covers the second strain relief construction. 15.The catheter of claim 1, wherein the at least one conducting member ofthe magnetic-based sensor assembly includes at least three conductingmembers, each of the at least three conducting members comprising arespective wire having respective first and second ends, each respectivewire comprising: a respective coil region wrapped on the support memberat a respective location along a length of the support member, and arespective joint region adjacent its respective coil region, therespective joint region comprising: a first respective connection of thefirst respective end of its respective wire to a respective cable memberat a first respective location proximal of its respective coil region,and a second respective connection of the second respective end of itsrespective wire to the respective cable member at a second respectivelocation proximal of its respective coil region, a first respectivestrain relief construction comprising a first respective plurality ofwindings of the respective cable member around the support member, and asecond respective strain relief construction comprising a secondrespective plurality of windings of the respective cable member aroundthe support member, the second respective plurality of windings of therespective cable member being spaced from the first respective pluralityof windings of the respective cable member; each respective cable memberbeing adapted to transmit a respective signal providing locationinformation from its respective conducting member to the mapping andlocalization system, and each respective joint region provides strainrelief to its respective coil region and its respective cable memberfrom detaching.
 16. The catheter of claim 15, wherein the secondrespective end of its respective wire extends through its respectivecoil region from a distal end of its respective coil region to thesecond respective location proximal of its respective coil region. 17.The catheter of claim 15, wherein the first respective end of itsrespective wire forms a first respective amount of slack in itsrespective wire between the proximal end of its respective coil regionand its first respective connection, and/or the second end of itsrespective wire forms a second respective amount of slack in itsrespective wire between the proximal end of its respective coil regionand its second respective connection.
 18. The catheter of claim 15,wherein each respective joint region further comprises a thirdrespective strain relief construction comprising a third respectiveplurality of windings of the respective cable member around the supportmember, the third respective plurality of windings of the respectivecable member being spaced from both the first respective plurality ofwindings of the respective cable member and the second respectiveplurality of windings of the respective cable member.
 19. The catheterof claim 18, wherein the windings of the third respective plurality ofwindings of the respective cable member are looser than the windings ofthe first respective plurality of windings of the respective cablemember and the windings of the second respective plurality of windingsof the respective cable member.